MILWAUKEE – What will happen tonight in Miller Park, or Sunday in Wrigley Field, or next week at Shea Stadium, will be a wonderful baseball accomplishment. Tom Glavine, who by all indications has never ingested anything worse than a can or two of light beer, who looks like he could be your accountant every bit as much as a major league pitcher, will win his 300th game.

That is a significant baseball moment. Baseball fans worldwide should stand up and take notice, because it is entirely possible we will never see that ever again, for as long as baseball is played.

It just isn’t a significant Mets moment, and Mets fans will be perfectly delighted tonight if they beat the Brewers and Aaron Heilman gets the win, if they beat the Cubs on Sunday and Pedro Feliciano gets the win, if they beat the Marlins the following Friday and Eric Gagne (dare to dream) gets the win.

It’s wonderful that Glavine will get this milestone as a Met, mostly because if he were getting it as a Brave – the way Glavine probably would have preferred it, truth be told – then the Mets might not presently be sitting five games ahead of Atlanta in the loss column with 56 games to go and with the Braves currently beefing up their roster for the dog days.

But we are making a silly miscalculation if we’re suddenly to paint Glavine as a man whose blood flows orange and blue, and if we’re immediately to expect Mets fans to invest more than a peripheral interest in Glavine’s joining the 300-win club.

Look, there is little doubt that when Glavine does slip across the threshold – whether he takes care of business tonight, or decides to join Alex Rodriguez and Barry Bonds in turning their milestone moments into a long candlelight vigil – he may well slam the door behind him. The news on Randy Johnson’s back isn’t good, and if he doesn’t recover and get the 16 wins he needs to join the club, it isn’t likely that Mike Mussina (244) or David Wells (235) have nearly enough career left to get there.

Three-hundred wins was already an all-but-impossible standard to reach anyway, even before the days of 35-start seasons and 100-pitch limits.

“As impressed as some people are by the men who reached 300, I’m more impressed when you see the names of the people who didn’t get there,” Tom Seaver told me four years ago, in the visitor’s dugout at Miller Park, a few days before Roger Clemens tried to join the 300-win club of which Seaver is a most humble member.

“Bob Gibson! Bob Feller! Whitey Ford! So many great pitchers. So many incredible names. Sandy Koufax! Fergie Jenkins! Jim Palmer! Carl Hubbell! I mean, you’re talking about legends, and these are fellows who, for one reason or another, never got a chance for 300 wins.”

So when Glavine gets there, he should be celebrated, he should be lauded, he should be appreciated, because he is one of the greatest left-handed pitchers to ever shave the outside corner. But win No. 300 will only be win No. 58 as a Met. That should keep the hyperventilating of Mr. Met to a minimum.

No amount of hoping and wishing will allow this to make up for the sad Mets fact that Seaver won No. 300 as a member of the White Sox, and that he actually fell two wins shy of 200 for his Mets career. Or that even Seaver concedes he would never have come anywhere close to 300 if he’d been forced to work for the abysmal Mets teams that would have ruined his prime (as they helped ruin Jerry Koosman’s, who somehow won 222 career games despite playing the last nine years of his career for haplessly run-challenged teams in New York, Minnesota, Chicago and Philadelphia).

Nor will it make up for the chilling fact that Dwight Gooden had a record of 100-39 on his 25th birthday, Nov. 6, 1989, and seemed as sure a sure thing to reach 300 as anyone who ever lived. Yet never even made it to 200.

Yes, whenever Glavine gets where he’s going, it will be as marvelous a baseball moment as whenever A-Rod gets to 500 and Ken Griffey gets to 600. We should all pause to recognize that wondrous accomplishment. Just don’t expect a strain of “Meet the Mets” to accompany it.